The remote host is missing an update to krb5 announced via advisory DSA 1766-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201766-1

Several vulnerabilities have been found in the MIT reference implementation of Kerberos V5, a system for authenticating users and services on a network. The Common Vulnerabilities and Exposures project identified the following problems: The Apple Product Security team discovered that the SPNEGO GSS-API mechanism suffers of a missing bounds check when reading a network input buffer which results in an invalid read crashing the application or possibly leaking information (CVE-2009-0844). Under certain conditions the SPNEGO GSS-API mechanism references a null pointer which crashes the application using the library (CVE-2009-0845). An incorrect length check inside the ASN.1 decoder of the MIT krb5 implementation allows an unauthenticated remote attacker to crash of the kinit or KDC program (CVE-2009-0847). Under certain conditions the the ASN.1 decoder of the MIT krb5 implementation frees an uninitialized pointer which could lead to denial of service and possibly arbitrary code execution (CVE-2009-0846). For the oldstable distribution (etch), this problem has been fixed in version 1.4.4-7etch7. For the stable distribution (lenny), this problem has been fixed in version 1.6.dfsg.4~beta1-5lenny1. For the testing distribution (squeeze), this problem will be fixed soon. For the unstable distribution (sid), this problem has been fixed in version 1.6.dfsg.4~beta1-13. We recommend that you upgrade your krb5 packages.